Machine key extractor



Jan. 11, 1944. G- ,1 BURS'TROM 2,339,143

l MACHINE' KEY EXTRACTOR Filed Nov. -5, 19411 .ur rpm .if ffm Patented Jan. 11, 1944 I UNITED STATES PATENT CFFICE MACHINE KEY EXTRACTOR Gustave A. Burstrom, New York, N. Y.

Application November 5, 1941, Serial No. 417,950

(Cl. 2li-86.1)

Claims.

This invention relates to a tool of very simple construction for pulling keys from machine parts, such as from pulleys and shafts or gears and shafts, and which is principally adapted for use for pulling plain keys or keys from which the gibs or teeth have been broken off, and which can therefore not be readily pulled with other types of tools.

More particularly, it is an aim of the invention to provide an improvement on the old conventional type of key chisel by the provision of a flexible joint or knee between the handle of the tool and the sharpened end of the tool bit or head.

Other objects and advantages of the invention will hereinafter become more fully apparent from the following description of the drawing, which illustrates a preferred embodiment of the invention, and wherein- Figure 1 is a Side elevational view of the tool,

Figure 2 is a fragmentary front elevational View of the bottom part thereof,

Figure 3 is a longitudinal sectional View taken substantially along the plane of the line 3 3 of Figure 1, and

Figure 4 is a longitudinal sectional view taken substantially along the plane of the line 4 4 of Figure 2, and showing the tool in an applied position.

Referring more particularly to the drawing, wherein like reference characters designate like or corresponding parts throughout the different views, Il) designates generally the improved key.

extractor or puller, and which includes an elongated handle I I having on one side of an end thereof an apertured ear or extension I2. The opposite side of the end of the handle I I, provided with the extension I2, is recessed at I3 to receive an elongated plate I4 which is detachably secured thereto by fastenings I5, and which is provided with an outer free end I6 forming an apertured ear, corresponding to the ear I2. The ears I2 and I3 combine to form a bifurcated end |'I of the handle I I, and the apertures of said ears are disposed in aiinement to receive trunnions I8 which project from opposite sides of the inner, enlarged end I9 of vthe head or bit 20 of the tool I0. The end I3 is provided with a rounded portion 2|, as seen in Figure 4, which bears against an inwardly bowed portion 22 of the handle II. The rounded portion 2| is provided With a shoulder 23 at one end thereof, and the inwardly bowed portion 22 is provided with a shoulder 24 which is disposed to face and be engaged by the shoulder 23. The head 20 is tapered from its enlarged end I8 toward its opposite, free end and is beveled on its inner side and at its free end to form a chisellike edge 25.

A leaf spring 26 has one end fastened by means of fastenings 2'I to the handle 'Ihe opposite, free end 28 of the spring 26 is bent outwardly and is disposed to bear against the inner side of the head or bit 2i) for urging said bit to swing outwardly and toward an extended position. The movement of the head or bit 20 toward an extended position relatively to the handle is restricted by engagement of the shoulder 23 with the shoulder 24, as seen in Figure 1, so that when the bit 20 is in an extended position relatively to the handle it is disposed substantially at an oblique angle thereto.

For the purpose of illustrating the application and use of the tool I0, in Figure 4 a portion of a pulley or gear is indicated at 29, a portion of a shaft, on which the pulley or gear 29 is mounted, is indicated at 33, and a key is shown at 3| for connecting the parts 29l and 30. To apply and operate the tool l0, the edge 25 of the head 23 is positioned against the key 3| and the rounded outer side 32 of the head 20 is disposed against the side of the gear or pulley 29 from which the key 3l projects. By then pushing downwardly on the handle the edge 25 will be caused to bit into the top surface of the key 3| and the rounded portion 32 will ride downwardly against the aforementioned side of the gear or pulley 29, thereby causing the bit 20 to swing relatively to the handle I I and against the action of the spring 2li for forcing the key 3| outwardly of the pulley or gear 29. The pressure exerted by the handle I I on the head 20 Will be borne by the contacting surfaces 2| and 22 so that none of the force will be exerted directly on the trunnions I8. The previously described operation for extracting the key 3l can be repeated as many times as is necessary to completely extract the key.

Various modifications and changes are contemplated and may obviously be resorted to, provided they fall within the spirit and scope of the invention as hereinafter defined by the appended claims, as only a preferred embodiment of the invention has been disclosed.

I claim as my invention:

1. A machine key extractor comprising a hanolle, a head pivotally connected to one end of said handle, said head having a rounded bearing surface adjacent one end and a sharpened free end adapted to engage and penetrate the surface of a key to be pulled and a rounded surface remote from said free end for bearing engagement with a part fastened by the key and at a different elevation from the sharpened free end, means for yieldably urging the head toward an extended position relatively to the handle, and means for restricting the swinging movement of the head, toward an extended position, and combining with said first mentioned means for normally positioning said sharpened free end longitudinally outwardly beyond the pivot or axis of the head and the head at an oblique angle to the longitudinal axis of the handle with said sharpened free end lowerinost.

2. A key extractor Comprising an elongated handle member, a head pivotally connected to one end of said handle member and having a rounded outer side adapted to bear against a gear or pulley from which a key is to be pulled, said head being provided with a sharpened free end adapted to penetrate the key to be pulled as the head rocks on said outer side, means for yieldably urging the head toward an extended position, and stop means for restricting the swinging movement of the head toward an extended position with said sharpened free end lowermost.

3. A key extractor comprising a handle having a bifurcated end, a head having a portion disposed between said bifurcated end, means for pivotally connecting the head to the bifurcated end, said head having a rocker surface and being provided at its lowest point with a sharpened free end adapted yto engage and penetrate a key to be pulled as the head rocks on said surface, means for yieldably urging the head toward an extended position relatively to the handle, and stop means for limiting the movement of the head toward said extended position.

4. A tool as in claim 3, said yieldable means comprising spring means carried by the handle for engaging and yieldably urging 4the head toward an extended position relatively to the handle.

5. A tool as in claim 3, said yieldable means comprising a leaf spring having an end fastened to the handle, the opposite, free end of the leaf spring being disposed to bear against the head for urging it toward `an extended position.

GUSTAVE A. BURSTROM. 

